Every time I see a trigger that could be a flow, it reminds me of Unicorns that could have been horses ;-)
Flow(or Process Builder) -> Invocable -> Apex function
Because this allows more logic to be declarative where it is easier to change and is easier to maintain
And it keeps the least amount of logic in code - by design
Why don't we use it more often?
(Maybe) because it's too obvious and common sense to just ignore - like wearing a mask, washing hands, brushing, etc.
What do we do instead?
Triggers, custom logic, custom trigger frameworks (Oh yes, it’s called job security in some circles )
Can Flow+Invocable do everything?
Nope. They have their limitations, like everything else. But, they can do a lot more than we use them for